~ Life on the Green Side

There’s only one Anemone that’s been bulletproof for us in East Texas. Years ago I was sauntering in the landscape of Alice Staub Liddell, a past-President of the Houston Garden Club of America. There’s a garden named for her on the campus of Rice University. Alice was a Houston socialite, philanthropist and friend. She was a close friend of Lynn Lowrey and we actually travelled together for several weeks in the mountains of Mexico in the 1980s. In her garden, I spotted an Anemone that Lynn had given her for safekeeping and I was quite impressed. While I had long admired the species, I had trouble getting them to thrive in East Texas. They would grow and flower but seemed to slowly decline over the years. I asked if I could divide the plant and she said, yes, of course. At SFA, the plant thrived and we passed it around here and there under her namesake. I’ve concluded it’s quite heat tolerant. I think it’s a hybrid and the official epithet would be Anemone X ‘Alice Staub’.

Taxonomically, Anemone × hybrida Paxton is normally considered a hybrid of Anemone hupehensis var. japonica and Anemone vitifolia, but, to be honest, I’m not sure from where ‘Alice Staub’ was originally derived nor it’s early history. I do remember Alice remarking it was one of the only Anemones she had found to do well in Houston soils and climate. There’s a clone that can be found in various mail order nurseries called ‘Alice’ and it may be the same. It forms large mounds of dark green interesting foliage and features 2-inch pinkish blooms on stems to three feet. It does run a bit cheerfully in the garden and appreciates morning sun.

Time passed and over a decade ago I gave a few to Janet and they prospered at her home in Shreveport. Years later I wanted to propagate it and I couldn’t find the plant at the SFA Gardens. I assumed it was extinct at SFA. I asked Janet if I could divide her plants and she acquiesced just as long as I promised I would bring her back some plants. I brought a bag of small plants back to SFA and remember turning them over to Dawn. Dawn denies that. She could be right. Before I knew it, I was Anemoneless. Janet never forgets anything and after some time began to ask, where are my plants? I said they are in process. Fortunately, Dawn finally recognized that my marriage was now in trouble. She found the plant somewhere in the garden, propagated plenty and we were back in business. The plant will be featured in the Spring 2018 plant sale and my marriage is back on track.

Sarah Weatherford, Student Assistant, with Anemone X ‘Alice Staub’

Anemones are interesting plants. There are over 200 species in the Ranunculaceae and they are generally native to temperate regions. Robert Fortune introduced the plant to England in 1844 from China, where he reported it was often found planted around graves. Anemone are appropriately called “wind flowers” as they sway on long stems in the slightest breeze. Jeff Abt, who just retired as the garden writer for the Nacogdoches Daily Sentinel really liked this plant and recognized it as a fine perennial in one of his long ago columns. Kudoes to Dawn for resurrecting it and bringing it back into our Nacogdoches family.

Magnolia pyramidata, the Pyramid magnolia, is a very rare tree, and in Texas it’s restricted to the eastern counties of Jasper and Newton in deeply wooded sandy ridges. You can tell it from southern magnolia and sweet bay by the deciduous leaves, about 9 inches long and 4 inches wide, with earlike lobes at the base and whorls around the stem. The terminal flowers are white and fragrant and the rosy-red seed pods are two and a half inches long and longer. To grow successfully it needs acidic, sandy, moist soils and at least a little shade. It makes a nice small tree and the seed pods are a real plus in late summer.

It calls home the rich woods and river bluffs, mostly in the coastal plain, sometimes lower piedmont. Never abundant, it is found in small colonies in Alabama, Florida, Georgia, Louisiana, Mississippii, South Carolina and Texas.

Magnolia pyramidata differs from the allopatric M. fraseri in being a smaller tree with a narrower, pyramidal habit; M. pyramidata is very local and nowhere abundant. Morphologically, M. pyramidata differs from M. fraseri in the pandurate leaf blades, smaller flowers and stipules, fewer stamens and pistils, and smaller follicetums. Magnolia pyramidata is occasionally cultivated, but it is less hardy than M. fraseri.

Seed are easy to germinate if not allowed to totally dry out. A month of stratification is sufficient.

In the last year, we have enjoyed hosting a number of botanists to the East Texas population. These expeditions are adventures in the special places of East Texas. We are unsure of the record tree, but an old report suggests that the largest known tree of Magnolia pyramidata may be in Texas. Over twenty years ago, this tree was 11.9m in height with a trunk diameter of 69 cm, was recorded from Newton County, Texas (American Forestry Association 1994). We will get it remeasured. In an expedition in August 2016, Keith Stephens led a motley crew of botanists, including Darren Duling, Greg Paige, Andrew Bunting, Peter Loos, Jerrel and Darrel Durham and others to the big tree on Campbell land. I am still looking for the circumference data and will post later.

Measuring the big one

Greg Paige of Bartlett Tree holding a branch with a fat seed pod

Emma Spence of the Morton Arboretum visited East Texas and collected tissue samples for DNA analysis. She was on the final leg of an across the South expedition to gather tissue from the different populations across the South. She was unable to find ANY wild populations left in Louisiana and it was apparent that development has taken a toll in our sister state to the East. The East Texas population is on Campbell Group land and Keith Stephens was wonderful to show us around with Emma. She was quick to announce that the colony population was greater than any of the sites in states to our East, estimated at over 1000 plants.

Emma Spence of the Morton Arboretum collecting tissue in July 2017 in East Texas for DNA analysis

For now, the champion tree is in Florida and in 2010 enjoyed a 68″ circumference and a height of 102 feet with a crown spread of 39′. Good friend Richard May was the finder of this amazing tree near Gadsden, Florida and took a couple of images for us to share. I now have pyramid magnolia envy.

Vitex rotundifolia – Is beach Vitex a beauty or a beast? Good grief! Isn’t this an invasive species? Isn’t this the dreaded “Kudzu of the beach” now threatening the Carolina dunes? Isn’t this the focus of all kinds of eradication campaigns? Why would any serious horticulturist even talk about a plant like this, much less write about it? Well, we’d just like to quietly point out that there many areas of the southern USA where it’s quite common in landscapes – and it’s simply just another interesting non-invasive exotic plant. That’s the case in our region of Texas. With over thirty years of experience with this hardy evergreen species in the USA – it’s an immigrant from Hawaii, believe it or not – we can now say there are many parts of the South where beach Vitex is rather tame. This is a species grown in fairly large numbers from a wide range of wholesale nurseries in Texas, Alabama, and Louisiana. Considering the fact that this is one tough immigrant from Hawaii, and the fact it’s easy to keep alive, it shouldn’t surprise anyone that it appears here to stay. Given a little positive horticulture, the plant can be downright beautiful, and it’s in that vein the plant can be used.

First, let’s give testimony and respect to the species as a landscape candidate, without discounting its invasive potential in areas where it finds itself too much at home. Writing this piece conjures up memories – twenty years ago – of some officials of the U.S. Fish and Wildlife Department visiting J.C. Raulston, Director of the North Carolina State University Arboretum, and suggesting to him that promoting, growing, thinking about or touching this plant was just about the most horrible thing a horticulturist could do. Yes, this plant is easy to grow. In coastal sandy spots, it can go where you don’t want it to, and when it’s there it can and will smother native vegetation. It can be a bad boy. So here’s the rule: In those sections of the country that beach Vitex is way too frisky for its own good, don’t plant it, and, when you see it, kill it. In our Zone 8 region of Texas, we have never seen a seedling . . . and if landscapers used the plant as described in this treatise, well, the end result is no problem. As a groundcover in our region, beach Vitex is not that voracious. At the San Antonio Botanical Garden in Texas (a bit warmer than Nacogdoches, Texas in the winter and summer), Paul Cox reports that it’s “manageable”. Knowing Paul Cox, that might not be too good. At any rate, experience is a good teacher.

First, how bad is this plant? Well, it is a native of the USA, but only because it comes from Hawaii. First introduced as an exciting groundcover over 30 years ago as a potential groundcover for sunny dry spots, this introduction made its way to the sand dunes of South Carolina, and it’s there that beach Vitex has come to be quite frightening. This brief note isn’t intended to stir up a fight in the horticultural crowd. The invasive exotic issue is real and one that deserves respect and attention. We know that. However, an invasive in one spot can be quite docile in another and it’s in that vein this article is presented.

If you happen to live in a region of the USA where beach Vitex never throws seedlings – and where it’s easily managed in a run – the plant does have attributes. We have long enjoyed it as a vine in our “line of vines” collection. The foliage is beautiful, clean and fully evergreen. The blooms are relatively inconspicuous coming in the fall as blue spikes. While attractive up close, they are never overwhelming. Our most conspicuous specimen in the Mast Arboretum “line of vines” was trained to a post and never failed to gain approval by visitors. We had evaluated this plant for over 20 years. Unfortunately, with some misunderstood directions, this old specimen was cut to the ground and destroyed by well-intentioned staff. A lost but not the end of the world. We’ve used the plant as a vine and as a groundcover and found that it responds to an occasional shearing. Once again, let me repeat, we’ve never seen a seedling in our Zone 8 garden (not that we won’t find one tomorrow!) –

As far as we’re concerned the Chinese evergreen dogwood is one durable plant. It’s been a surprise here in East Texas for over two decades. Given a little soil drainage and some protection from the western sun, it develops into a fine specimen small tree. The bloom show on a good sized tree can be stunning, a cloak of white flowers for several weeks in mid summer. The blooms are followed by interesting sweet red fruits which are edible. While not about to take over the grocery chains in the South, they are good. Extremely useful in a famine my friends in China would say. In our winters the foliage remains dark green with only the harshest winter turning foliage slightly purple. In particularly cold winters further North into Zone 7, the foliage might drop. We have offered this tree for years in our plant sale and most find the tree easy to grow and pest free. This is one of our favorite trees and we highly recommend growing one in your garden!

A seven year old tree in the Gayla Mize Garden

So far, the trees do not appear to be invasive. Even though we’ve allowed plenty of fruit drop, we’ve yet to see a problem. Time will tell.

Propagation by seed is easy. One month cold and moist is suggested and then sow in a community flat. Cuttings can be taken anytime but percentages are often low. It is best to take May-June cuttings and root them under frequent mist.

There is one variety we have in the collection, “Empress of China”. It was selected by the great plantsman John Elsley for exceptional bloom count, beautiful fruit and great garden vigor. It touts glossy, leathery bright green leaves. In theGayla Mize garden we have planted a long line of seedlings of this tree and there are differences here and there but they’re not dramatic. Some seedlings do seem to have better flowers and we’ll continue to see if anything is worth introducing. Right now, it strikes me that seedlings are solid and perform well.

For a mid summer show, this small tree is a surprise. While available, it’s yet to be a market mover in Texas. We think East Texas and across the Gulf South will make a fine home for this tough as nails ornamental.

I’ve concluded that Hibiscus dasycalyx, the Neches river rose mallow, is certainly in danger of being lost in the wild. Intrusion by other mallows seems to favor the invader, whether H. moscheuotis, H. militaris, or H. laevis. Where they comingle come progeny sharing a fairly friendly gene pool. It’s a modest megacharasmatic endangered plant with a neat story. Known in the wild from only four populations in East Texas, it must be noted that the species has found a home in over a dozen reintroduction projects, as well as in Southern Arboretums, botanical gardens and home landscapes. While no barn burner in the market, it has moved into all kinds of horticultural and nursery channels across the South. Along the way, as professional and amateur horticulturists and breeders are known to do, it’s been used to produce a range of interesting hybrids. The long narrow leaves are unique and incorporating that aesthetic into progeny with large red, pink, or white flowers, well, it’s done. Given half a chance, this wetland species will survive in a home landscape. To be totally cheerful, all it needs is a naturally wet site, good sun, and you can’t let the spot grow into a forest.

First a little botany: Hibiscus dasycalyx is a shrubby-appearing herbaceous perennial that grows 0.8-2.3 meters in height. The glabrous leaves are narrow and deeply lobed, and the flowers are white to cream with a crimson throat. The calyx is densely covered with long hairs, and the seeds are densely reddish hairy. The specific epithet “dasycalyx” translates from the Greek to mean a fruit-covering that is “shaggy” or “thick-haired”. Blake (1958) commented that the species is distinguishable from all other United States Hibiscus spp. because of its densely spreading hirsute calyx. An obligate wetland species (Reed 1986), H. dasycalyx is a member of Section Muenchhusia (n=19), a group of five closely related Hibiscus species that are uniquely designated “rose mallows” (Blanchard 1976). The rose-mallows may have evolved recently and all are in floodplain or coastal plain wetland habitats of the eastern U. S., the western boundary being East-Texas north to Canada. Seed dispersal for this group appears to be entirely water-dependent.

Hibiscus dasycalyx in flower July 2017

Diversity in the plot: H. lavevis (?) and H. dasycalyx.

Rarity: Ecological and Genetic Status

The four known locations of H. dasycalyx are wetland habitats within floodplain plant communities of large creeks (Houston Co. and Cherokee Co.) and in major river bottoms (Trinity Co.). These plant community types have been termed by Nixon (1985)
as Wet Creek Bottom and River Bottom Communities. Within these communities, Hibiscus dasycalyx occupies open slough and oxbow habitats that experience periodic flooding. The Trinity County site is on the Neches River floodplain and was discovered by Ivan Shiller in 1955. This original site was later designated the type locality by Blake (1958). In 1978, 23 years later, a second population was found by Claude McLeod on Tantaboque Creek, a tributary of the Trinity River in Houston County.

Old image of Jeff Williams, SFASU ATCOFA, and a colony near Ponte, Texas

In 1988, when only two locations were known, investigators found that the type locality of H. dasycalyx had already been severely disturbed (McMahan 1988). Paul Cox (1988) and Elray Nixon reported that “all but two plants had been dredged up from an expanded drainage project and were resprouting in a soil bank about three meters above the former water level”. The third documented population on Mud Creek, a tributary of the Angelina River in Cherokee County, was found in 1992 by Jason Singhurst (Carr 1992). It too has suffered over the years (mowing, herbicides, etc.).

In the early 1990s it was noted that all four populations are in serious decline. Surveys performed by TNHP staff and Warnock in slough and oxbow habitats have produced negative findings (Orzell 1990, Warnock 1995). Over the past years, cursory searches have been conducted in potential habitat around highway-river crossings in at least 35 counties. Habitat reduction by drainage and filling of sloughs and oxbows, prevention of oxbow production, and channelization have likely negatively impacted H. dasycalyx populations (Warnock 1995). In addition to habitat reduction, genetic drift appears to be a major threat to this extremely rare species. The two wide-spread and closely related H. laevis and H. moscheutos are found growing in the same or nearby wetland habitats. Apparent hybrids with H. moscheutos have been found at the Trinity Co. and Houston Co. populations. Hybrids with H. laevis have also been noted at the Cherokee Co. site.

Orland Blanchard (1976) conducted thesis research on the Hibiscus section Trionum Sensu Lato in 1976. Blanchard’s research included morphological descriptions, systematics, hybridization studies, and distribution/habitat information for H. dasycalyx. In 1992, Klips hypothesized that H. dasycalyx is a product of diploid hybridization speciation between two wide-spread sympatric closely related species, H. laevis All. (halberd-leaf rose-mallow) [syn. H. militaris Cav.] and H. moscheutos. Klips (1995) studied morphological relationships and conducted electrophoretic screening on the three species and determined that H. dasycalyx is probably not the product of hybridization but perhaps a recent offshoot from the interfertile and morphologically similar H. laevis. The genetic relationships among these three Hibiscus species and the potential for current and future genetic-swamping of the rare H. dasycalyx has been reported (Blanchard 1976, Klips 1995, Warnock 1995). Despite these questions, many investigators continue to recognize H. dasycalyx as a distinct species as concluded in early work (Gould 1975, Correll & Johnson 1979, Nixon 1985). The debate remains.

RELATED RESEARCH

Research on H. dasycalyx has been conducted by Texas-based agencies and institutions, including the Texas Natural Heritage Program (TNHP), the Texas Nature Conservancy (TNC), the CPC at Mercer Arboretum and at the San Antonio Botanical Gardens (SABG), the Texas Regional Institute for Environmental Studies (TRIES, Sam Houston State University), the Stephen F. Austin State University (SFASU) Arboretum and the USFWS in Houston and Austin. These organizations have reported on the status of survey, habitat and plant vigor, and/or propagation of H. dasycalyx (Cox 1988, Orzell 1990, San Antonio Botanical Center 1990, Smith & Creech 1995). Blanchard (1976) and the San Antonio Botanical Center (1990) have reported successful cultivation of H.dasycalyx. Likewise, Erin Smith, SFASU graduate research assistant, conducted rooting experiments from stem cuttings, seed germination and fertilization trials in 1994 and 1995 (Smith & Creech 1995). Additional stem-cutting propagation and fertilizer trials were conducted by the author in 1995 on cultivated plants of H. dasycalyx. In general, these studies indicated favorable rooting percentages of softwood cuttings under mist with photoperiod interruption.

A variety of ecology research has been published on other rose-mallows. This information can be useful in the formulation of a conservation strategy for H. dasycalyx because of the similarities in habitat niche and reproductive strategy of these species. Genetic affinities between H. laevis and Florida-endemic H. coccineus have been studied by Wise and Menzel (1971), elucidating a lineage with H. dasycalyx. Also important is the fact that all of the rose-mallows appear to be pollinated primarily by Ptilothrix bombiformis Cresson (Anthophoridae), a non-social bee that is a Hibiscus specialist (Blanchard 1976; Spira 1989). Therefore, study of the pollination ecology of other rose-mallows may be pertinent to the understanding of H. dasycalyx’s current status and future chances as a self-sustaining species. Research on the pollination ecology (Spira et al. 1996, Spira et al. 1992), pollen competitive ability (Snow & Spira 1994), selfed progeny vigor (Snow & Spira 1993), seed predation and reproductive success (Spira 1987) has been conducted for the wide-spread rose-mallow, H. moscheutos. In addition, dissertation research is available on the community production and biomass allocation of H. moscheutos (Cahoon 1982) as well as on the distribution, herbivory, and seed set problems of southeastern Hibiscus spp (Cochis 1964; Robbins 1985). Observations from these investigations can guide the development of appropriate strategies for the augmentation of H. dasycalyx at in-situ and ex-situ locations.

Cultivation research has been conducted on other rose-mallows as well. H. moscheutos has been cultivated for ornamental use in the United States since the mid 1800’s (Welch & Grant 1995). For the establishment and maintenance of cultivated H. moscheutos, which is a heavy feeder, an annual application of a balanced fertilizer is recommended (Giles et al. 1980). Propagation and horticultural care information on both H. moscheutos and H. laevis (syn. H. militaris) can be found ubiquitously in gardening literature (Griffiths et al. 1992). The Landscape Restoration Handbook lists these two rose-mallows as native species suitable for introduction into marshy habitats in the Southeast U. S. (Harker et al. 1993). The Handbook provides information on plant type, environmental tolerances, aesthetic value, wildlife value, flower color, bloom period, and landscape use for over 3300 native plant species.

Conservation and Recovery Strategies

Prior to the addition of H. dasycalyx to the Category 1 candidate list, Warnock (1995) indicated that there were no mechanisms for protection of this rose-mallow since known populations are subject to mowing, discing, bulldozing, herbicide use, drainage, genetic swamping from sympatric rose-mallows, genetic drift and, potentially, are subject to over-collecting. Unless the species is listed as endangered or threatened, either at the state or federal level, the remaining H. dasycalyx plants and its habitat cannot be protected or managed for conservation (Warnock 1995).

Listing a rare plant species is not a panacea, however. The 1973 Endangered Species Act (ESA) may prevent the federal government and private citizens from harassing or killing listed animal species on both public and private land, but there are no prohibitions from destroying threatened and endangered plant species by private citizens on private land (Doughty & Parmenter 1989). Since the federal government is prohibited from the extirpation of threatened and endangered plants, federally funded or managed projects are required to mitigate activities to ensure conservation. Because the majority of the known occurrences of H. dasycalyx are found on private land, listing by the federal government may have little effect on the destiny of this species. Listing or not, the key to recovery of this Hibiscus is the implementation of cooperative agreements among federal and state agencies, institutions, and private land owners.

While it was once the priority of the USFWS to explore conservation possibilities that could avoid the listing of H. dasycalyx as endangered (Nemec pers. comm. 1996), the species is now listed. While rare plant management can involve many different methods, there is an increasing need for population re-introduction and restoration to be a part of the recovery plan (Falk 1987). Re-introduction is defined as the intentional establishment of a plant species where it has become extirpated for the purpose of establishing a self-sustaining population (Maunder 1992). In order to implement re-introduction and restoration, cultivation studies need to be implemented. It is obvious that the primary goal of conservation research on a given species is not horticultural knowledge, but such knowledge is necessary to develop techniques for cultivating rare species as a means to an end (Affolter 1997).

For H. dasycalyx, conservation strategies recommended by Warnock (1995) include the cultivation of plants to ensure against catastrophic loss, to prepare for re-introductory work, and to provide for scientific and educational activities. However, Ashton (1987) asserts that genetic viability of remaining populations of rare plants must be estimated before a conservation strategy is executed. This research requires funding. It is unknown when or if H. dasycalyx will be federally listed and when funding will be allocated for genetic viability research and conservation strategy design, initiation and implementation. While genetic viability is being ascertained for any rare species, immediate propagation and development of controlled ex-situ sites can check over-collecting due to potential horticultural value and curb destructive and unethical collection into the future (Mc Cartney 1995). As for H. dasycalyx, it appears that ex-situ preservation measures need to be taken soon since habitat preservation is tenuous for the three existing populations. Species such as H. dasycalyx, which have fewer than five locations, may become extinct if a chance event causes a population crash (Falk 1992). In addition to the threat of continued habitat degradation, Klips (1995) suggests that H. dasycalyx should be isolated from H. laevis and H. moscheutos to avoid dilution by gene flow when establishing preserves. Since hybridization is occurring at all three of the natural populations, this recommendation excludes them as re-introduction sites. In the interim, Mill Creek Gardens can provide a safe ex-situ site for cultivated H. dasycalyx because the site is isolated from all other Hibiscus species. Continued propagation and monitoring would be under the auspices of the Stephen F. Austin State University Arboretum. Since funding for the implementation of conservation projects is affected by federal, state, and industry politics, many plans are not implemented or can occur piecemeal over time. Augmentation via propagation and establishment in ex-situ sites needs to be initiated while waiting for the necessary bureaucratic processes to occur.

RESEARCH PLOTS, NACOGDOCHES, TX

Experimental Design

A randomized complete block design (RCBD) was used for this H. dasycalyx fertilizer and mulching trial. Plants were randomly divided into groups of four and randomly assigned to three blocks of eight groups each. 32 plants were planted in each of three blocks, giving a total of 96 plants. Treatments were randomly assigned to 24 experimental units (plots) containing four plants each, with each treatment appearing exactly once in every block. Between the four rates of fertilizer and two mulching regimes, there are eight different treatments per block. The blocks are 6.1 by 12.2 meters (20 by 40 feet). The plots are 3.05 by 3.05 meters (10 by 10 feet).

Broad overview of the terrain adjacent to plots

In September of 1995, 96 plants were selected from several hundred plants using guidelines regarding morphologically correct features for the species. A portion of the H. dasycalyx plants used were stem cuttings taken from a single plant that had been propagated from the type locality and grown at the SFASU Arboretum. The rest of the plants used were progeny of these cutting-grown plants. The seeds were germinated and the cuttings were rooted and grown in the SFASU Arboretum greenhouse; then hardened off in one gallon cans in an outdoor shade house from 1994 to 1995. A selection protocol was followed because putative hybrids with H. moscheutos occur at the type locality. Appendix 3 provides a comparison of morphological features among H. dasycalyx, H. moscheutos, and H. laevis (Warnock 1995).

The fertilization and mulching experiment on H. dasycalyx at the Mill Creek Gardens research site was initiated in October of 1995 and concluded in November of 1996. Two separate applications at four rates of slow release 14-14-14 OsmocoteÒ fertilizer was made during the trial, once during planting (October 18, 1995) and again, approximately one month after dormancy-break (March 21, 1996). The slow release fertilizer is encapsulated within multiple layers of polymeric resin. When water vapor penetrates the permeable shell and dissolves the nutrient core, the resulting osmotic pressure within the granule meters the liquid nutrients through the coating and into the surrounding soil/media (Scotts 1995). 14-14-14 OsmocoteÒ is coated to provide approximately 4 months, based on an average soil temperature of 70°F. Some use can occur in the winter months by an herbaceous perennial such as H. dasycalyx, via absorption and storage in the roots.

Research plots

Treatments

The fall application (10/18/95) of the four rates (0, 18, 36, and 72 g) was applied in-ground and as a top-dress (total application was 0, 36, 72, and 144g). The fertilizer was mixed into the soil/mulch directly below the roots as the plantings were made. The top-dress was applied within the root zone (10 cm radius) of the plants. The spring application (3/21/96) was a repeat of the 0, 18, 36, and 72 g rates as a top-dress only. Therefore, total fertilizer application for the study was 0, 54, 108, and 216g per plant. In the dry soil plots “wells” of soil/mulch were constructed around the root zones. In the standing-water plots plastic collars were placed around the plants to hold the fertilizer prills within the root zones. To further avoid intra-specific interaction of root zones and fertilization, the plantings were made at least a meter apart.

The low application rate (54g/plant) is equivalent to applying 12lbs of fertilizer per 100 plants or 1.9 ounces per plant. In terms of pounds per square-foot, the low rate is equivalent to .36 lbs/ft2. For 14% NPK, the low application rate is approximately .05 lbs/ft2 of each of the nutrients.

For plots selected to receive mulch, two gallons were mixed in the planting hole and four gallons of mulch was applied as top-dress around the plant. All holes were dug uniformly to accommodate the addition of mulch. For each non-amended plant, the soil was simply returned to the planting hole with the appropriate rate of fertilizer.

Plants were watered at the end of planting time (10/18/95) and then again on 10/28/95 due to drought conditions. Weed removal was conducted once during the study. In mid September 1996, all plants were removed within a 20 cm radius of each H. dasycalyx, regardless of their perceived threat.

Results

Stacy Scott collected data for three years (1196, 1997 and 1998). Results concluded that mulch and fertilizer (applied at planting) improved plant performance three years in a row.

Influence of fertilizer, mulch, and soil condition on growth, stem number and capsule number

Influence of fertilizer on mulched and non-mulched plants

We concluded fertilizer treatments did help plant growth and long term survival. Mulch did not. What was most interesting is that even though fertilizer was applied only in the first year, the benefits of that application were still significantly apparent three years later. Perhaps the additional growth in the first year allowed the fertilized plants to compete with weeds later in the plant’s life.

RESEARCH PLOT REVISITED IN 2013

Dr. Dave Kulhavy and students revisited the plots in 2013 and mapped the plants. Data collected included plant height and number of stalks per plant.

Number of Stalks and Plant Height distribution

With this data, Dr. Kulhavy and students placed plants in categories based on stalk number. Because stalk number is some indication of plant size and age, it could be demonstrated that in nearly twenty years, the plants have a fluid presentation across the site.

Dr. Dave Kulhavy and students in summer of 2013 mapping the colony

Distribution of plants by number of stalks in 2013

Large plants inside and outside the original plots.

GENETIC VIABILITY RESEARCH NEEDED

A major issue surrounding the propagation and re-introduction of extremely rare species such as H. dasycalyx is the small number of plants that exist. Would re-introduction involving the propagation of a few individuals (a narrow genetic base) warrant the time and expense of such a project? The CPC (1991) recommends that between 10 and 50 individuals could preserve a significant fraction of the genetic information within that population. As of 1995, the three populations of H. dasycalyx contain as few as several to perhaps no more than 60 plants, and because each of the populations are hybridizing with H. moscheutos or H. laevis, it is likely that this sampling criteria will not be met for this species. Some investigators suggest that dozens of genetic individuals are needed to preserve fit genotypes in progeny (Guerrant 1992; Ashton 1978). However, this assertion may be based on theoretical assumptions or on animal studies and does not necessarily characterized long-term or species-specific plant studies (Eloff and Powrie 1990). New populations of plants are often started by one or several founding individual(s) and have become genetically viable and self-sustaining. One example cited by Eloff and Powrie (1990) involved the establishment of three plants of Aloe spectabilis (Aloeaceae) transplanted in 1900 to a location genetically isolated from any colony of Aloe. The original three plants produced a population whose numbers have increased to about 10,000 plants. These investigators indicate that at least with Aloe spectabilis, three plants were sufficient to establish a self-sustaining population with apparently the same diversity as the original colony.

Amber Miller, USFW, during a July 6, 2017 survey of the reintroduction plot

Even if the CPC’s recommended sampling criteria is met, it is argued that ex-situ conservation of a small genetic sample can lead to unpredictable changes in gene frequencies and loss of gene combinations (Ashton 1978). Some investigators assert, further, that the use of genetically “depauperate” or cloned material will doom a project because of the genetic homogeneity of the re-introduced individuals (Maunder 1992; Gordon 1994). There is no question that artificial augmentation terminates the natural selection process, but is it necessarily true that the use of small samples causes deleterious or undesirable gene combinations? Stebbins (1950) states that, as a matter of course, naturally rare plant species evolve thoroughly exposed to inbreeding and that depression is unlikely to occur. The answer is species and strategy specific. More research is needed in the arena of founder effects and population bottlenecks involving naturally rare plant species before decisions are made to forego conservation of them. An excellent examination of extinction probability and minimal viable population (MVP) regarding the conservation of rare plant species can be found in Conservation Biology (Fiedler and Jain 1992).

CONSERVATION HORTICULTURE

Closer to the focus of this research is “conservation horticulture,” defined by Affolter (1997) as the application of techniques and the knowledge base of horticulture to rare plant conservation. The technical aspects of a re-introduction project for endangered plant species must be logistically feasible or the effort is academic (Falk and Olwell 1992). The technical feasibility questions posed by Falk and Olwell (1992) are: Is there enough re-introduction material? Are propagation and transplanting techniques being studied? What are the interim management needs of newly transplanted material? Horticulturists have begun to respond to the concerns of managers who are struggling with the huge task of rare plant management. The International Conference on Botanic Gardens and the World Conservation Strategy (Bramwell 1987) encouraged the involvement of botanic gardens in conservation action; botanic gardens should maintain, propagate and make available stock of threatened species for scientific and horticultural research. The International Conference stated that no single approach to the conservation of endangered species can be relied upon; therefore, ex-situ conservation is a necessary adjunct to in-situ conservation (Bramwell 1987). Given (1987) lists five reasons why botanic gardens and arboreta should grow plants for conservation purposes (p.104):

To have as many threatened species in cultivation as practicable as an insurance against their loss in the wild.

To cultivate critically threatened species in sufficient numbers so as to prevent significant genetic erosion.

To have material available for research and for assessment for economic use.

To have collections of plants available for educational programs and for public displays.

To propagate and maintain plants suitable for use in programs, to reintroduce species into the wild, or to reinforce wild populations.

Since the late eighties, the CPC and the Botanic Gardens Conservation International (BGCI) have instituted standards for documentation, study, and maintenance of rare plant collections at ex-situ sites (BGCI 1993; Wieland 1995).

HORTICULTURAL RESEARCH OF H. DASYCALYX

There is very little information regarding the cultural and maintenance needs of nursery-grown H. dasycalyx for establishment in wildland situations has been published. This information is needed because horticultural treatments, such as fertilization and mulching, may positively affect survivorship, establishment and biomass and reproductive vigor (Poincelot 1980, Vitousek 1982, Merwin and Stiles 1994, Boodley 1996). Plants require an adequate nutrient supply for proper growth, sexual maturity and senescence (Barbour, et al 1987). In the case of some ex-situ habitats, “mitigation” introduction sites, and re-introduction locations which have incurred ground-disturbing activities, soil nutrients may be in short supply or out of balance (Vitousek 1982). Nitrogen is usually the limiting nutrient in many communities, particularly following disturbances. Other cultural treatments such as mulching can maximize growth and availability of essential plant nutrients (Merwin and Stiles 1994). Poincelot (1980) characterizes mulches as the ultimate conservation agent: mulches increase soil moisture retention, mitigate soil erosion, provide a temporary barrier to competition, and mediate soil temperature.

Generally, optimizing plant growth by whatever means, can give the target plant an initial competitive edge over other plants already established in the community. Response of plant vigor in the rare H. dasycalyx during the first year of establishment to fertilization and mulching provides feasibility information for the implementation of ex-situ and re-introduction projects. Equally as important, this study also provides first year anecdotal field observations on inter-specific competition, microhabitat differences regarding moisture regime, and herbivory at this ex-situ location.

Robbins, J. T. 1985. The distribution and taxonomy of selected Malvaceae occurring in the southeastern United States and their influence on feeding and ovipositional behavior of the Boll Weevil, Anthonomus grandis Boheman. Ph.D. dissertation, Mississippi State University, Mississippi State, MS, 103 pp.

Touching ancient trees is a habit of many of my tree obsessed friends. It’s a connection humans can make with the past, present and future. Some of my more spiritual friends think it transfers a kind of cosmic energy from one to the other and vice versa. I’m not sure about that, but I like the idea.

Janet and I at the big one, Tane Mahuta, May 13 2017

In early May 2017, Janet and I made the trek to the North part of the North Island in New Zealand to visit the last remnant of the ancient Kauri forest. The Kauri tree is Agathis australis which is one of a relatively small genus of 22 species. It’s an evergreen tree, a member of the Araucariaceae family of conifers and was once widespread during the Jurassic, now restricted primarily to the Southern hemisphere. The bark is smooth and light grey to grey-brown, usually peeling into irregular flakes. The lowest branches fall away, leaving circular scars. The juvenile leaves are larger than in adults, more or less acute. The male pollen cones appear usually only on larger trees after seed cones have appeared. The female seed cones usually develop on short lateral branchlets, maturing after two years.

Male pollen cone and female cone

The original forest was logged heavily in the last of the 19th century and first half of the 20th century. The kauri was popular because it enjoyed a straight bole free of knots and made excellent masts for ocean faring ships. The timber is generally straight-grained and of fine quality with an exceptional strength-to-weight ratio and rot resistance, making it ideal for yacht hull construction.. The wood is commonly used in the manufacture of guitars and ukuleles due to its light weight and relatively low price of production. It is also used for some Go boards (goban). The uses of the New Zealand species (A. australis) included shipbuilding, house construction, wood panelling, furniture making, mine braces, and railway sleepers. Various species of kauri also yield various resins that have value. While only 2% of the original forest now remain, what’s there is protected and under the conservation ethos of the Māori, the original settlers of New Zealand.

You can tell a lot about a culture in how they greet each other. For some, a hongi is a traditional Māori greeting in New Zealand. It is done by pressing one’s nose and forehead to another person at an encounter. With a hongi, the ha, or breath of life, is exchanged and intermingled and is thought to share the souls of both involved. Through the hongi a person is no longer a visitor but is instead part of the people of the land. With that status, one is obliged to share in all the activities and duties of the people there. In long ago times, that meant bearing arms in battles or in tending crops and harvesting the bounty of the earth. So the hongi is a tradition that involves sharing the breath of life, an act that comes directly from the Gods.

Janet planting a hongi on the ancient one

Tāne Mahuta is the big one. Its age has been estimated at between 1,250 and 2,500 years. It is the largest kauri known to stand today. The Māori name is the name of a God and means “Lord of the Forest”. There are other giant kauri nearby with the second largest being Te Matua Ngahere. The “Four Sisters” are nearby and thought to be siblings that made their home together. Tāne Mahuta is certainly the most famous tree in New Zealand. While known to the Māori well before European settlers landed, the stand wasn’t identified until the 1920s when road contractors were surveying for the road that how runs through the forest.

Te Matua Ngahere

In the Māori creation myth, Tāne is the son of Ranginui, the sky father, and Papatuanuku, the earth mother. In this legend, Tāne separates his parents from their marital embrace until his father the sky was high above mother earth. Tāne then sets about clothing his mother with flora and fauna. These are regarded as Tāne’s children. In 1971, the tree had a trunk girth of 45.2 ft. with a trunk height of 58 ft. The total height of the tree was 168 feet and the trunk volume has been estimated at 8630 cubic ft. Total volume of wood estimated at 18,250 cubic feet.

There’s a serious threat to the remaining Kauri. From the Forest Phytophthoras of the World website: (http://forestphytophthoras.org/species/agathidicida ), I offer the following: “In 1972 a Phytophthora was associated with dead and dying trees in a kauri forest stand on Great Barrier Island, an island off the northern New Zealand coast . Symptoms included yellowing of foliage, canopy thinning and occasional tree death. The causative organism was identified as P. heveae by J. Stamps of the Commonwealth Mycological Institute. In 2006, Phytophthora ‘taxon Agathis’ was reported from kauri in a forest west of Auckland on regenerating and mature trees. The original identification of the causative organism as P. heveae was questioned, as the ITS–sequence of the isolate obtained from the Great Barrier Island and those from the mainland since 2006 was identical to P. castaneae. This raised the possibility that the kauri Phytophthora was a new species within Clade 5 of the genus (Blair et al. 2008). The ‘Kauri killing’ Phytophthora organism has been now formally described as Phytophthora agathidicida B.S. Weir, Beever, Pennycook & Bellgard (Weir et al., 2015), distinct from P. castaneae and other species of Phytophthora.” There’s no doubt the disease has made its way in to the Waipoua forest and the trail entrances are equipped with sanitizers to spray the soles of shoes of any visitors, who are encouraged not to wander in the forest but to stay on the trails. The shallow roots of the kauri tree are particularly susceptible to infection and dead and dying trees are nearby. The long term prospects for the kauri tree will now rest with scientists who are feverishly screening for resistant seedlings with the hope that replanting will insure the forest remains. Still, the long term prospects are seen as dismal and the chance to stand in the shade of these giants may not be with us forever.

At the head of the trail into the Kauri forest there are precautions to take

Like so few of us, this fellow gets better with age. While Persian Ironwood is not overly encumbered with a blinding floral display, this tree makes up for it with great form, bark interest, good Fall color, and a durable disposition in the garden. Given a little time (OK, ten years or more), this tree will create a lively conversation. Best performance in the Deep South is to keep the tree in a spot that’s slightly acidic, medium moisture, and well drained. That said, this tree has been through the grinder here, from freezes, droughts, and blasting heats to floods and tornadoes and hurricanes, and they just keep on trucking.

The genus name recognizes the founder F.W. Parrot (1792-1841) who was a German Naturalist. Parrotia persica is a small, single to multi-trunk deciduous tree that will top out at 20-40′ tall. The flowers lack petals and are comprised of reddish stamens surrounded by brown bracts and they appear before leaves appear. With a good hand lens, you might call them pretty. Fall color is a key feature with most showing off with a butterscotch to yellow as temperatures cool in the Fall. With age, the bark exfoliates to show green, white or tan patches beneath and it’s quite striking the older a tree gets.

Flowers will not win best in show but are attractive on close inspection

The bark is a key feature . . .

There are varieties. We’ve worked hard to get the pendulous form and have has several that never panned out. I acquired three that were fakes before finally getting the real thing. I think it’s a Kew England plant under many names but ‘Kew’s weeping’ is the real deal. It’s strongly weeping and defines the word slow. We are rooting it and if I hand you a one gallon it means I like you. Special plant for someone looking to be edgy. We have one cultivar named ‘Biltmore’ and I assume it’s from the big tree there but it looks like the straight species to me. ‘Vanessa’ is another variety, and does seem to feature a slightly different foliage look in the Fall and is perhaps a bit more upright. Don’t have an opinion on whether it’s really smaller statured. There are other varieties reported but we haven’t found them. P. persica ‘Bella’ features upright branches and widely serrated ovate leaves. These leaves are reported as deep-purple when young and then mature to a rich green colour. The leaves are also reported to twist slightly, which adds further interest. P. persica ‘Horizontalis’ is a semi-weeping variety with wide spreading horizontal branching. P. persica ‘Jodrell Bank’ is supposedly more of an upright form. P. persica ‘Pendula’ is passed around as a weeper but when folks ask, I say “not so much.” I don’t know anything about a clone called P. persica ‘Select’ which is reported to have purple-edged new leaves that become uniformly green after the first flush.

Parrotia subaequalis should be a rage. It’s related to P. persica but very rare and only recently introduced. What’s odd about P. subaequalis is that it was found in eastern China, about 3500 miles away from the natural range of P. persica. Another odd fact is this tree was a recent find, first characterized by Deng in 1992. Arnold Arboretum had small plants in the garden in 2004. From that auspicious start, the plant has been scattered far and wide. We’re contributing to that. What’s sad for me is I saw the plant at the Nanjing Botanical Garden years ago but assumed it was P. persica and never gave it a second glance, chalking it up to Chinese nomenclature issues. I never caught it in the Fall because that’s what separates the two immediately. It’s brilliant red.

Parrotia subaequalis in the Fall

SFA Gardens Dec 2017

Easy to root and grow, we are multiplying P. subaequalis as fast as we can. If we give you one, it means we like you. There’s a great story in Arnoldia that every fan of the Hamamelidaceae should read:

I don’t think I’ve ever met a plant enthusiast who didn’t find this tree special and the conversation wanders into why it doesn’t make a top ten list somewhere. I guess it’s the lack of flowers? Maybe it’s because it’s so slow to get going? Maybe we’re just not that fond of Persia in the Deep South? It’s just not well known in the South and rarely encountered in the nursery trade, never seen at the mass markets. For whatever reason, this tough and durable tree is worthy of any well drained full sun spot in the Southern garden.

Baluchistan in the 1980s was a different time. As an American, as a USAID consultant for the fruit industry, I was treated by my hosts in fine fashion. After all, the money was flowing into the country from various aid agencies. Pakistan was having to deal with hundreds of thousands of refugees from the Russian/Afghanistan war and the USA was helping the Pashtuns, the second largest ethnic group in Pakistan. They were Afghans. So, at the time, I was one of the good guys. My first encounter with a chaste tree in the wild was in a narrow dry mountain valley in this western province. The white to lavender blooms were dancing above the finely cut leaves of ten to fifteen foot shrubby trees that ran along the stream. This is the home of the chaste tree. For centuries farmers had captured the mountain run off of these streams into stone aqueducts that carried the flow out of the canyons down into valleys and then into small canals that split and split again to feed fruit orchards, vegetable farms and local villages. A system of waterways are the Karez irrigation system of the region and they serve as more than just an irrigation source. They tie farmers, villagers, and communities together in a long history of water rights, cooperation and wars. When we talk about water wars, this place wins. Along the run of the flow out of the mountains, the adjacent lands prospered. This is one of the natural homes of the Chaste tree.

Columbia Park, Shreveport, LA

Vitex agnus-castus is an ancient tree. It’s home is a wide swath across the Mediterranean. It enjoys many names including hemp tree, chaste tree, chasteberry, Abraham’s balm, and monk’s pepper. Vitex agnus-castus is a bit different from related Vitex species in that it can tolerate some winter freezing without dying. The tree was used in basketry. However, I cannot verify if its reputation as an anaphrodisiac is true. That means anti-libido. You might have seen it coming. Chaste tree? Monk’s pepper? At any rate, it is reported to have been used in men’s prison to keep the more festive males in check. There are reports sailors made good use of it during their long voyages on the sea. Just the name Monk’s pepper implies something; I’m not sure what. Anyway, the ground seed does look a lot like pepper and I can attest it tastes a little like pepper, but I never really wanted to overindulge. I can also testify that the rumor that Hillary Clinton was going to make it the state tree of New York is patently false. It’s just another darn example of that fake news problem.

Vitex agnus-castus can be cut back annually and will still rebloom

Long naturalized here and there, the species has been in cultivation in the South since 1670. The chaste tree is a butterfly attractant and sports showy blue, white, mauve, or pinkish blooms from May into September. This small tree can be left to reach 10 -15’ in height or whacked back to more desired proportions. If the spent blooms are cut away, the tree returns with another vigorous show of flowers. While exceptionally drought resistant, the chaste tree appreciates a good garden soil and moisture and vigorous plants mean longer and more dramatic inflorescences. In the north, the species can be effectively used as a perennial. Since it blooms on new growth it cannot be knocked out of a bloom show even when frozen close to the ground. Vitex is easy to root. While considered to be a cross-pollinating plant, single plants will self pollinate and make seed as well.

The variety ‘LeCompte’ is a nice form with long blue inflorescences and it came from the town of LeCompte, Louisiana. It was captured out of a home landscape by Greg Grant and a van load of SFA students. The story goes that the van screeched to a stop, the doors flew open, the cuttings were liberated, an escape was made good and the whole escapade took less than fifteen seconds. It may not be true but it does lend credence to the adage that if you have ten horticulturists in a room you’re looking at nine thieves.

LeCompte

There are many varieties. Salinas Pink and Flora Ann are introductions that showcase pinkish blooms with Flora Ann the pinkest in the trade. Both are Greg Grant introductions. These two provide a little different twist to the normal blues, lavenders and whites of most varieties in the trade.

Vitex agnus-castus ‘Flora Ann’ is a Greg Grant introduction and still the best pink

A current variety trial near the coliseum parking lot runs from North to South.itex agnus-castus has a long and interesting history. It’s a plant with a story. It’s tough, drought resistant and reliably flowers. It may have value if you’re locked in a prison cell and need to keep your mind properly focused. It attracts bees and butterflies. If you don’t like the way it’s acting, you can cut it all the way to the ground and it’ll return that spring and be flowering by summer. Texas A & M University named it a Texas Superstar and branded it with yet another name. It’s now promoted as the “Texas Lilac”, which I objected to simply because it’s not a darn lilac (Syringa species) and it’s not really a Texan. It just immigrated here. My protest went nowhere and I’m more convinced than ever that fake news is winning.

Back in late May, 1998, Greg Grant and I were admiring a particular Wisteria frutescens in the SFA Mast Arboretum’s “lines of vines”, a collection of 96 vines on posts. The plant was found by Lynn Lowrey, legendary plant hunter, near the dam of a lake in southeast Texas that was oddly named Dam B. We were discussing the merits of the plant. It had nice-sized blooms for the species, clean foliage, good texture, a little repeat blooming, and had been easy to keep in bounds. There we were scratching our heads for a good name when in a flash, one of those pesky bumble bees made a dive at Greg’s head. He rocked backwards took a swat at the critter and muttered, “Damn bee”. I said, “That’s it! We’ll name it Dam B.” After all, the plant was collected at Dam B. To Greg and I, the name made sense but the problem remained with the spelling. Should we go with “Dam B” or “Damn Bee”? This created a healthy debate on who might or might not be offended. Were there better names out there, or would this grab the public attention to plant more native Wisterias? We never really settled the issue, couldn’t come up with a better name, and the inspiration soon left the both of us so the name ‘Dam B’ stuck. Over the years, the clone has been passed around and can be found in commerce, either as ‘Dam B’, or occasionally as ‘Lowrey’, and rarely as ‘Damn Bee’.

‘Dam B’ sports light blue/lavender, finely scented, pendulous flowers in six-to-ten inch long racemes that mix perfectly with the fine-textured foliage. This plant enjoys a heavy flowering season in late May and June and then blooms lightly and sporadically throughout the summer and into the fall. Pruning and deadheading certainly encourages repeat blooming. Our specimen “on a stick” was easy to keep in bounds and the suckers from the crown are easy to take care of in comparison to their Asian cousins.

Wisteria frutescens ‘Dam B’

‘Dam B’

This selection of Wisteria frutescens has been with us many years and I have seen it at other locations; it’s a promising candidate for the southern gardener wanting a less rambunctious vine with wisteria-like charm. There are other Wisteria frutescens to consider. ‘Amethyst Falls’ out of Head-Lee Nursery in South Carolina remains a popular standard, sports dark bluish purple popcorn like blooms and is popular because it never sets seed which allows it to bloom repeatedly. We have Wisteria frutescens ‘alba,’ the white flowering form and another seedling in the Arboretum. ‘Memphis Blue’ enjoys a long true blue inflorescence. ‘Longwood Purple’ is another dark flowered popcorn bloom form. Our collection also includes three selections by Maarten van der Giessen of Best Liners of Semmes, Alabama and they look strong. Our latest acquisition is a “pink” form found by Peter Loos and Matt Welch several years ago near Pascagoula, Mississippi. While not a sizzling hot pink, there’s enough pink there to give us hope for future selections.

Wisteria frutescens ‘Peter’s Pink’ really is kind of pink

‘Peter’s Pink’

Wisteria frutescens is native, hardy, drought-tolerant and much better behaved than those closely-related, yet less civilized Asian cousins, Wisteria floribunda, the Japanese wisteria and Wisteria sinensis, the Chinese wisteria. The main problem with these two brutes is growth rate. A vigorous Chinese or Japanese Wisteria can become a monster if left untended for very long (like overnight). Root suckers can gain an incredible foothold far from camp. Plant Wisteria frutescens.

Propagation is easy. Softwood cuttings under mist in June and we have had good success with hardwood cuttings taken in late winter. All Wisterias appreciate full sun, a well-drained soil and good horticulture during the establishment years. A three year old vine is here to stay, quite capable of dealing with heat, drought, cold, floods, and the gardener’s neglect and occasionally, abuse. Tough plants for a tough place on earth.

Is beach Vitex a beauty or a beast? Isn’t this an invasive species? Isn’t this the dreaded “Kudzu of the beach” now threatening the Carolina dunes? Isn’t this the focus of all kinds of eradication campaigns? Why would any serious horticulturist even talk about a plant like this, much less write about it? Well, we’d just like to quietly point out that there are many areas of the southern USA where it’s quite common in landscapes – and it’s simply just another interesting non-invasive exotic plant. That’s the case in our region of Texas. It’s no thug here.

Beach vitex in the lines of vines

With over thirty years of experience with this hardy evergreen species in the USA – it’s an immigrant from Hawaii, believe it or not – we can now say there are many parts of the South where beach Vitex is rather tame. This is a species grown in fairly large numbers from a wide range of wholesale nurseries in Texas, Alabama, and Louisiana. Considering the fact that this is one tough immigrant from Hawaii, and the fact it’s easy to keep alive, it shouldn’t surprise anyone that it appears here to stay. Given a little positive horticulture, the plant can be downright beautiful, and it’s in that vein the plant can be used. First, let’s give testimony and respect to the species as a landscape candidate, without discounting its invasive potential in areas where it finds itself too much at home. Writing this piece conjures up memories – thirty years ago – of some officials of the U.S. Fish and Wildlife Department visiting J.C. Raulston, Director of the North Carolina State University Arboretum, and suggesting to him that promoting, growing, thinking about or touching this plant was just about the most horrible thing a horticulturist could do.

Beach vitex makes a big trunk when trained on a post

Yes, this plant is easy to grow. In coastal sandy spots, it can go where you don’t want it to, and when it’s there it can and will smother native vegetation. It can be a bad boy. So here’s the rule: In those sections of the country that beach Vitex is way too frisky for its own good, don’t plant it, and, when you see it, kill it. In our Zone 8 region of Texas, we have never seen a seedling and if landscapers used the plant as described in this treatise, well, the end result is no problem. As a groundcover in our region, beach Vitex is not that voracious. At the San Antonio Botanical Garden in Texas (a bit warmer than Nacogdoches, Texas in the winter and summer), Paul Cox reported that it’s “manageable”. Knowing Paul Cox, that might not be too good. At any rate, experience is a good teacher.

First, how bad is this plant? Well, it is a native of the USA, but only because it comes from Hawaii. First introduced as an exciting groundcover over 30 years ago as a potential groundcover for sunny dry spots, this introduction made its way to the sand dunes of South Carolina, and it’s there that beach Vitex has come to be quite frightening. This brief note isn’t intended to stir up a fight in the horticultural crowd. The invasive exotic issue is real and one that deserves respect and attention. We know that. However, an invasive in one spot can be quite docile in another and it’s in that vein this article is presented.

Lines of vines in the old days, two thugs side by side?

If you happen to live in a region of the USA where beach Vitex never throws seedlings – and where it’s easily managed in a run – the plant does have attributes. We have long enjoyed it as a vine in our “line of vines” collection. The foliage is beautiful, clean and fully evergreen. The blooms are relatively inconspicuous coming in the fall as blue spikes. While attractive up close, they are never overwhelming. Our most conspicuous specimen in the Mast Arboretum “line of vines” has been trained to a post and never fails to gain approval by visitors. We’ve used the plant as a vine and as a groundcover and found that it responds to an occasional shearing. Once again, let me repeat, we’ve never seen a seedling in our Zone 8 garden (not that we won’t find one tomorrow!) – and in our garden it’s not that vigorous, nor does it generate much fear and loathing. That said, tread with trepidation.